readconf.h

   1 /* $OpenBSD: readconf.h,v 1.157 2024/09/25 23:01:39 jsg Exp $ */
   2
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Functions for reading the configuration file.
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  */
  15
  16 #ifndef READCONF_H
  17 #define READCONF_H
  18
  19 /* Data structure for representing option data. */
  20
  21 #define SSH_MAX_HOSTS_FILES     32
  22 #define PATH_MAX_SUN            (sizeof((struct sockaddr_un *)0)->sun_path)
  23
  24 struct allowed_cname {
  25         char *source_list;
  26         char *target_list;
  27 };
  28
  29 typedef struct {
  30         char   *host_arg;       /* Host arg as specified on command line. */
  31         int     forward_agent;  /* Forward authentication agent. */
  32         char   *forward_agent_sock_path; /* Optional path of the agent. */
  33         int     forward_x11;    /* Forward X11 display. */
  34         int     forward_x11_timeout;    /* Expiration for Cookies */
  35         int     forward_x11_trusted;    /* Trust Forward X11 display. */
  36         int     exit_on_forward_failure;        /* Exit if bind(2) fails for -L/-R */
  37         char   *xauth_location; /* Location for xauth program */
  38         struct ForwardOptions fwd_opts; /* forwarding options */
  39         int     pubkey_authentication;  /* Try ssh2 pubkey authentication. */
  40         int     hostbased_authentication;       /* ssh2's rhosts_rsa */
  41         int     gss_authentication;     /* Try GSS authentication */
  42         int     gss_deleg_creds;        /* Delegate GSS credentials */
  43         int     password_authentication;        /* Try password
  44                                                  * authentication. */
  45         int     kbd_interactive_authentication; /* Try keyboard-interactive auth. */
  46         char    *kbd_interactive_devices; /* Keyboard-interactive auth devices. */
  47         int     batch_mode;     /* Batch mode: do not ask for passwords. */
  48         int     check_host_ip;  /* Also keep track of keys for IP address */
  49         int     strict_host_key_checking;       /* Strict host key checking. */
  50         int     compression;    /* Compress packets in both directions. */
  51         int     tcp_keep_alive; /* Set SO_KEEPALIVE. */
  52         int     ip_qos_interactive;     /* IP ToS/DSCP/class for interactive */
  53         int     ip_qos_bulk;            /* IP ToS/DSCP/class for bulk traffic */
  54         SyslogFacility log_facility;    /* Facility for system logging. */
  55         LogLevel log_level;     /* Level for logging. */
  56         u_int   num_log_verbose;        /* Verbose log overrides */
  57         char   **log_verbose;
  58         int     port;           /* Port to connect. */
  59         int     address_family;
  60         int     connection_attempts;    /* Max attempts (seconds) before
  61                                          * giving up */
  62         int     connection_timeout;     /* Max time (seconds) before
  63                                          * aborting connection attempt */
  64         int     number_of_password_prompts;     /* Max number of password
  65                                                  * prompts. */
  66         char   *ciphers;        /* SSH2 ciphers in order of preference. */
  67         char   *macs;           /* SSH2 macs in order of preference. */
  68         char   *hostkeyalgorithms;      /* SSH2 server key types in order of preference. */
  69         char   *kex_algorithms; /* SSH2 kex methods in order of preference. */
  70         char   *ca_sign_algorithms;     /* Allowed CA signature algorithms */
  71         char   *hostname;       /* Real host to connect. */
  72         char   *tag;            /* Configuration tag name. */
  73         char   *host_key_alias; /* hostname alias for .ssh/known_hosts */
  74         char   *proxy_command;  /* Proxy command for connecting the host. */
  75         char   *user;           /* User to log in as. */
  76         int     escape_char;    /* Escape character; -2 = none */
  77
  78         u_int   num_system_hostfiles;   /* Paths for /etc/ssh/ssh_known_hosts */
  79         char   *system_hostfiles[SSH_MAX_HOSTS_FILES];
  80         u_int   num_user_hostfiles;     /* Path for $HOME/.ssh/known_hosts */
  81         char   *user_hostfiles[SSH_MAX_HOSTS_FILES];
  82         char   *preferred_authentications;
  83         char   *bind_address;   /* local socket address for connection to sshd */
  84         char   *bind_interface; /* local interface for bind address */
  85         char   *pkcs11_provider; /* PKCS#11 provider */
  86         char   *sk_provider; /* Security key provider */
  87         int     verify_host_key_dns;    /* Verify host key using DNS */
  88
  89         int     num_identity_files;     /* Number of files for identities. */
  90         char   *identity_files[SSH_MAX_IDENTITY_FILES];
  91         int    identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
  92         struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
  93
  94         int     num_certificate_files; /* Number of extra certificates for ssh. */
  95         char    *certificate_files[SSH_MAX_CERTIFICATE_FILES];
  96         int     certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
  97         struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
  98
  99         int     add_keys_to_agent;
 100         int     add_keys_to_agent_lifespan;
 101         char   *identity_agent;         /* Optional path to ssh-agent socket */
 102
 103         /* Local TCP/IP forward requests. */
 104         int     num_local_forwards;
 105         struct Forward *local_forwards;
 106
 107         /* Remote TCP/IP forward requests. */
 108         int     num_remote_forwards;
 109         struct Forward *remote_forwards;
 110         int     clear_forwardings;
 111
 112         /* Restrict remote dynamic forwarding */
 113         char  **permitted_remote_opens;
 114         u_int   num_permitted_remote_opens;
 115
 116         /* stdio forwarding (-W) host and port */
 117         char   *stdio_forward_host;
 118         int     stdio_forward_port;
 119
 120         int     enable_ssh_keysign;
 121         int64_t rekey_limit;
 122         int     rekey_interval;
 123         int     no_host_authentication_for_localhost;
 124         int     identities_only;
 125         int     server_alive_interval;
 126         int     server_alive_count_max;
 127
 128         u_int   num_send_env;
 129         char    **send_env;
 130         u_int   num_setenv;
 131         char    **setenv;
 132
 133         char    *control_path;
 134         int     control_master;
 135         int     control_persist; /* ControlPersist flag */
 136         int     control_persist_timeout; /* ControlPersist timeout (seconds) */
 137
 138         int     hash_known_hosts;
 139
 140         int     tun_open;       /* tun(4) */
 141         int     tun_local;      /* force tun device (optional) */
 142         int     tun_remote;     /* force tun device (optional) */
 143
 144         char    *local_command;
 145         int     permit_local_command;
 146         char    *remote_command;
 147         int     visual_host_key;
 148
 149         int     request_tty;
 150         int     session_type;
 151         int     stdin_null;
 152         int     fork_after_authentication;
 153
 154         int     proxy_use_fdpass;
 155
 156         int     num_canonical_domains;
 157         char    **canonical_domains;
 158         int     canonicalize_hostname;
 159         int     canonicalize_max_dots;
 160         int     canonicalize_fallback_local;
 161         int     num_permitted_cnames;
 162         struct allowed_cname *permitted_cnames;
 163
 164         char    *revoked_host_keys;
 165
 166         int      fingerprint_hash;
 167
 168         int      update_hostkeys; /* one of SSH_UPDATE_HOSTKEYS_* */
 169
 170         char   *hostbased_accepted_algos;
 171         char   *pubkey_accepted_algos;
 172
 173         char   *jump_user;
 174         char   *jump_host;
 175         int     jump_port;
 176         char   *jump_extra;
 177
 178         char   *known_hosts_command;
 179
 180         int     required_rsa_size;      /* minimum size of RSA keys */
 181         int     enable_escape_commandline;      /* ~C commandline */
 182         int     obscure_keystroke_timing_interval;
 183
 184         char    **channel_timeouts;     /* inactivity timeout by channel type */
 185         u_int   num_channel_timeouts;
 186
 187         char    *ignored_unknown; /* Pattern list of unknown tokens to ignore */
 188 }       Options;
 189
 190 #define SSH_PUBKEY_AUTH_NO      0x00
 191 #define SSH_PUBKEY_AUTH_UNBOUND 0x01
 192 #define SSH_PUBKEY_AUTH_HBOUND  0x02
 193 #define SSH_PUBKEY_AUTH_ALL     0x03
 194
 195 #define SSH_CANONICALISE_NO     0
 196 #define SSH_CANONICALISE_YES    1
 197 #define SSH_CANONICALISE_ALWAYS 2
 198
 199 #define SSHCTL_MASTER_NO        0
 200 #define SSHCTL_MASTER_YES       1
 201 #define SSHCTL_MASTER_AUTO      2
 202 #define SSHCTL_MASTER_ASK       3
 203 #define SSHCTL_MASTER_AUTO_ASK  4
 204
 205 #define REQUEST_TTY_AUTO        0
 206 #define REQUEST_TTY_NO          1
 207 #define REQUEST_TTY_YES         2
 208 #define REQUEST_TTY_FORCE       3
 209
 210 #define SESSION_TYPE_NONE       0
 211 #define SESSION_TYPE_SUBSYSTEM  1
 212 #define SESSION_TYPE_DEFAULT    2
 213
 214 #define SSHCONF_CHECKPERM       1  /* check permissions on config file */
 215 #define SSHCONF_USERCONF        2  /* user provided config file not system */
 216 #define SSHCONF_FINAL           4  /* Final pass over config, after canon. */
 217 #define SSHCONF_NEVERMATCH      8  /* Match/Host never matches; internal only */
 218
 219 #define SSH_UPDATE_HOSTKEYS_NO  0
 220 #define SSH_UPDATE_HOSTKEYS_YES 1
 221 #define SSH_UPDATE_HOSTKEYS_ASK 2
 222
 223 #define SSH_STRICT_HOSTKEY_OFF  0
 224 #define SSH_STRICT_HOSTKEY_NEW  1
 225 #define SSH_STRICT_HOSTKEY_YES  2
 226 #define SSH_STRICT_HOSTKEY_ASK  3
 227
 228 /* ObscureKeystrokes parameters */
 229 #define SSH_KEYSTROKE_DEFAULT_INTERVAL_MS       20
 230 #define SSH_KEYSTROKE_CHAFF_MIN_MS              1024
 231 #define SSH_KEYSTROKE_CHAFF_RNG_MS              2048
 232
 233 const char *kex_default_pk_alg(void);
 234 char    *ssh_connection_hash(const char *thishost, const char *host,
 235     const char *portstr, const char *user, const char *jump_host);
 236 void     initialize_options(Options *);
 237 int      fill_default_options(Options *);
 238 void     fill_default_options_for_canonicalization(Options *);
 239 void     free_options(Options *o);
 240 int      process_config_line(Options *, struct passwd *, const char *,
 241     const char *, char *, const char *, int, int *, int);
 242 int      read_config_file(const char *, struct passwd *, const char *,
 243     const char *, Options *, int, int *);
 244 int      parse_forward(struct Forward *, const char *, int, int);
 245 int      parse_jump(const char *, Options *, int);
 246 int      parse_ssh_uri(const char *, char **, char **, int *);
 247 int      default_ssh_port(void);
 248 int      option_clear_or_none(const char *);
 249 int      config_has_permitted_cnames(Options *);
 250 void     dump_client_config(Options *o, const char *host);
 251
 252 void     add_local_forward(Options *, const struct Forward *);
 253 void     add_remote_forward(Options *, const struct Forward *);
 254 void     add_identity_file(Options *, const char *, const char *, int);
 255 void     add_certificate_file(Options *, const char *, int);
 256
 257 #endif                          /* READCONF_H */